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1da177e4 LT |
1 | /*!***************************************************************************** |
2 | *! | |
0779bf2d ML |
3 | *! Implements an interface for i2c compatible eeproms to run under Linux. |
4 | *! Supports 2k, 8k(?) and 16k. Uses adaptive timing adjustments by | |
1da177e4 LT |
5 | *! Johan.Adolfsson@axis.com |
6 | *! | |
7 | *! Probing results: | |
8 | *! 8k or not is detected (the assumes 2k or 16k) | |
9 | *! 2k or 16k detected using test reads and writes. | |
10 | *! | |
11 | *!------------------------------------------------------------------------ | |
12 | *! HISTORY | |
13 | *! | |
14 | *! DATE NAME CHANGES | |
15 | *! ---- ---- ------- | |
16 | *! Aug 28 1999 Edgar Iglesias Initial Version | |
17 | *! Aug 31 1999 Edgar Iglesias Allow simultaneous users. | |
18 | *! Sep 03 1999 Edgar Iglesias Updated probe. | |
19 | *! Sep 03 1999 Edgar Iglesias Added bail-out stuff if we get interrupted | |
20 | *! in the spin-lock. | |
21 | *! | |
1da177e4 LT |
22 | *! (c) 1999 Axis Communications AB, Lund, Sweden |
23 | *!*****************************************************************************/ | |
24 | ||
1da177e4 LT |
25 | #include <linux/kernel.h> |
26 | #include <linux/sched.h> | |
27 | #include <linux/fs.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/delay.h> | |
30 | #include <linux/interrupt.h> | |
7e920426 | 31 | #include <linux/wait.h> |
7c0f6ba6 | 32 | #include <linux/uaccess.h> |
1da177e4 LT |
33 | #include "i2c.h" |
34 | ||
3d6c03fc | 35 | #define D(x) |
1da177e4 LT |
36 | |
37 | /* If we should use adaptive timing or not: */ | |
3d6c03fc | 38 | /* #define EEPROM_ADAPTIVE_TIMING */ |
1da177e4 LT |
39 | |
40 | #define EEPROM_MAJOR_NR 122 /* use a LOCAL/EXPERIMENTAL major for now */ | |
41 | #define EEPROM_MINOR_NR 0 | |
42 | ||
43 | /* Empirical sane initial value of the delay, the value will be adapted to | |
44 | * what the chip needs when using EEPROM_ADAPTIVE_TIMING. | |
45 | */ | |
46 | #define INITIAL_WRITEDELAY_US 4000 | |
47 | #define MAX_WRITEDELAY_US 10000 /* 10 ms according to spec for 2KB EEPROM */ | |
48 | ||
49 | /* This one defines how many times to try when eeprom fails. */ | |
50 | #define EEPROM_RETRIES 10 | |
51 | ||
52 | #define EEPROM_2KB (2 * 1024) | |
53 | /*#define EEPROM_4KB (4 * 1024)*/ /* Exists but not used in Axis products */ | |
54 | #define EEPROM_8KB (8 * 1024 - 1 ) /* Last byte has write protection bit */ | |
55 | #define EEPROM_16KB (16 * 1024) | |
56 | ||
57 | #define i2c_delay(x) udelay(x) | |
58 | ||
59 | /* | |
60 | * This structure describes the attached eeprom chip. | |
61 | * The values are probed for. | |
62 | */ | |
63 | ||
64 | struct eeprom_type | |
65 | { | |
66 | unsigned long size; | |
67 | unsigned long sequential_write_pagesize; | |
68 | unsigned char select_cmd; | |
69 | unsigned long usec_delay_writecycles; /* Min time between write cycles | |
70 | (up to 10ms for some models) */ | |
71 | unsigned long usec_delay_step; /* For adaptive algorithm */ | |
72 | int adapt_state; /* 1 = To high , 0 = Even, -1 = To low */ | |
73 | ||
74 | /* this one is to keep the read/write operations atomic */ | |
4f0447b8 | 75 | struct mutex lock; |
1da177e4 LT |
76 | int retry_cnt_addr; /* Used to keep track of number of retries for |
77 | adaptive timing adjustments */ | |
78 | int retry_cnt_read; | |
79 | }; | |
80 | ||
81 | static int eeprom_open(struct inode * inode, struct file * file); | |
82 | static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig); | |
83 | static ssize_t eeprom_read(struct file * file, char * buf, size_t count, | |
84 | loff_t *off); | |
85 | static ssize_t eeprom_write(struct file * file, const char * buf, size_t count, | |
86 | loff_t *off); | |
87 | static int eeprom_close(struct inode * inode, struct file * file); | |
88 | ||
89 | static int eeprom_address(unsigned long addr); | |
90 | static int read_from_eeprom(char * buf, int count); | |
91 | static int eeprom_write_buf(loff_t addr, const char * buf, int count); | |
92 | static int eeprom_read_buf(loff_t addr, char * buf, int count); | |
93 | ||
94 | static void eeprom_disable_write_protect(void); | |
95 | ||
96 | ||
97 | static const char eeprom_name[] = "eeprom"; | |
98 | ||
99 | /* chip description */ | |
100 | static struct eeprom_type eeprom; | |
101 | ||
102 | /* This is the exported file-operations structure for this device. */ | |
5dfe4c96 | 103 | const struct file_operations eeprom_fops = |
1da177e4 LT |
104 | { |
105 | .llseek = eeprom_lseek, | |
106 | .read = eeprom_read, | |
107 | .write = eeprom_write, | |
108 | .open = eeprom_open, | |
109 | .release = eeprom_close | |
110 | }; | |
111 | ||
112 | /* eeprom init call. Probes for different eeprom models. */ | |
113 | ||
114 | int __init eeprom_init(void) | |
115 | { | |
4f0447b8 | 116 | mutex_init(&eeprom.lock); |
1da177e4 LT |
117 | |
118 | #ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE | |
119 | #define EETEXT "Found" | |
120 | #else | |
121 | #define EETEXT "Assuming" | |
122 | #endif | |
123 | if (register_chrdev(EEPROM_MAJOR_NR, eeprom_name, &eeprom_fops)) | |
124 | { | |
125 | printk(KERN_INFO "%s: unable to get major %d for eeprom device\n", | |
126 | eeprom_name, EEPROM_MAJOR_NR); | |
127 | return -1; | |
128 | } | |
129 | ||
130 | printk("EEPROM char device v0.3, (c) 2000 Axis Communications AB\n"); | |
131 | ||
132 | /* | |
133 | * Note: Most of this probing method was taken from the printserver (5470e) | |
134 | * codebase. It did not contain a way of finding the 16kB chips | |
135 | * (M24128 or variants). The method used here might not work | |
136 | * for all models. If you encounter problems the easiest way | |
137 | * is probably to define your model within #ifdef's, and hard- | |
138 | * code it. | |
139 | */ | |
140 | ||
141 | eeprom.size = 0; | |
142 | eeprom.usec_delay_writecycles = INITIAL_WRITEDELAY_US; | |
143 | eeprom.usec_delay_step = 128; | |
144 | eeprom.adapt_state = 0; | |
145 | ||
146 | #ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE | |
147 | i2c_start(); | |
148 | i2c_outbyte(0x80); | |
149 | if(!i2c_getack()) | |
150 | { | |
151 | /* It's not 8k.. */ | |
152 | int success = 0; | |
153 | unsigned char buf_2k_start[16]; | |
154 | ||
155 | /* Im not sure this will work... :) */ | |
156 | /* assume 2kB, if failure go for 16kB */ | |
157 | /* Test with 16kB settings.. */ | |
158 | /* If it's a 2kB EEPROM and we address it outside it's range | |
159 | * it will mirror the address space: | |
160 | * 1. We read two locations (that are mirrored), | |
161 | * if the content differs * it's a 16kB EEPROM. | |
162 | * 2. if it doesn't differ - write different value to one of the locations, | |
163 | * check the other - if content still is the same it's a 2k EEPROM, | |
164 | * restore original data. | |
165 | */ | |
166 | #define LOC1 8 | |
167 | #define LOC2 (0x1fb) /*1fb, 3ed, 5df, 7d1 */ | |
168 | ||
169 | /* 2k settings */ | |
170 | i2c_stop(); | |
171 | eeprom.size = EEPROM_2KB; | |
172 | eeprom.select_cmd = 0xA0; | |
173 | eeprom.sequential_write_pagesize = 16; | |
174 | if( eeprom_read_buf( 0, buf_2k_start, 16 ) == 16 ) | |
175 | { | |
176 | D(printk("2k start: '%16.16s'\n", buf_2k_start)); | |
177 | } | |
178 | else | |
179 | { | |
180 | printk(KERN_INFO "%s: Failed to read in 2k mode!\n", eeprom_name); | |
181 | } | |
182 | ||
183 | /* 16k settings */ | |
184 | eeprom.size = EEPROM_16KB; | |
185 | eeprom.select_cmd = 0xA0; | |
186 | eeprom.sequential_write_pagesize = 64; | |
187 | ||
188 | { | |
189 | unsigned char loc1[4], loc2[4], tmp[4]; | |
190 | if( eeprom_read_buf(LOC2, loc2, 4) == 4) | |
191 | { | |
192 | if( eeprom_read_buf(LOC1, loc1, 4) == 4) | |
193 | { | |
194 | D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", | |
195 | LOC1, loc1, LOC2, loc2)); | |
196 | #if 0 | |
197 | if (memcmp(loc1, loc2, 4) != 0 ) | |
198 | { | |
199 | /* It's 16k */ | |
200 | printk(KERN_INFO "%s: 16k detected in step 1\n", eeprom_name); | |
201 | eeprom.size = EEPROM_16KB; | |
202 | success = 1; | |
203 | } | |
204 | else | |
205 | #endif | |
206 | { | |
207 | /* Do step 2 check */ | |
208 | /* Invert value */ | |
209 | loc1[0] = ~loc1[0]; | |
210 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
211 | { | |
212 | /* If 2k EEPROM this write will actually write 10 bytes | |
213 | * from pos 0 | |
214 | */ | |
215 | D(printk("1 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", | |
216 | LOC1, loc1, LOC2, loc2)); | |
217 | if( eeprom_read_buf(LOC1, tmp, 4) == 4) | |
218 | { | |
219 | D(printk("2 loc1: (%i) '%4.4s' tmp '%4.4s'\n", | |
220 | LOC1, loc1, tmp)); | |
221 | if (memcmp(loc1, tmp, 4) != 0 ) | |
222 | { | |
223 | printk(KERN_INFO "%s: read and write differs! Not 16kB\n", | |
224 | eeprom_name); | |
225 | loc1[0] = ~loc1[0]; | |
226 | ||
227 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
228 | { | |
229 | success = 1; | |
230 | } | |
231 | else | |
232 | { | |
233 | printk(KERN_INFO "%s: Restore 2k failed during probe," | |
234 | " EEPROM might be corrupt!\n", eeprom_name); | |
235 | ||
236 | } | |
237 | i2c_stop(); | |
238 | /* Go to 2k mode and write original data */ | |
239 | eeprom.size = EEPROM_2KB; | |
240 | eeprom.select_cmd = 0xA0; | |
241 | eeprom.sequential_write_pagesize = 16; | |
242 | if( eeprom_write_buf(0, buf_2k_start, 16) == 16) | |
243 | { | |
244 | } | |
245 | else | |
246 | { | |
247 | printk(KERN_INFO "%s: Failed to write back 2k start!\n", | |
248 | eeprom_name); | |
249 | } | |
250 | ||
251 | eeprom.size = EEPROM_2KB; | |
252 | } | |
253 | } | |
254 | ||
255 | if(!success) | |
256 | { | |
257 | if( eeprom_read_buf(LOC2, loc2, 1) == 1) | |
258 | { | |
259 | D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", | |
260 | LOC1, loc1, LOC2, loc2)); | |
261 | if (memcmp(loc1, loc2, 4) == 0 ) | |
262 | { | |
263 | /* Data the same, must be mirrored -> 2k */ | |
264 | /* Restore data */ | |
265 | printk(KERN_INFO "%s: 2k detected in step 2\n", eeprom_name); | |
266 | loc1[0] = ~loc1[0]; | |
267 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
268 | { | |
269 | success = 1; | |
270 | } | |
271 | else | |
272 | { | |
273 | printk(KERN_INFO "%s: Restore 2k failed during probe," | |
274 | " EEPROM might be corrupt!\n", eeprom_name); | |
275 | ||
276 | } | |
277 | ||
278 | eeprom.size = EEPROM_2KB; | |
279 | } | |
280 | else | |
281 | { | |
282 | printk(KERN_INFO "%s: 16k detected in step 2\n", | |
283 | eeprom_name); | |
284 | loc1[0] = ~loc1[0]; | |
285 | /* Data differs, assume 16k */ | |
286 | /* Restore data */ | |
287 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
288 | { | |
289 | success = 1; | |
290 | } | |
291 | else | |
292 | { | |
293 | printk(KERN_INFO "%s: Restore 16k failed during probe," | |
294 | " EEPROM might be corrupt!\n", eeprom_name); | |
295 | } | |
296 | ||
297 | eeprom.size = EEPROM_16KB; | |
298 | } | |
299 | } | |
300 | } | |
301 | } | |
302 | } /* read LOC1 */ | |
303 | } /* address LOC1 */ | |
304 | if (!success) | |
305 | { | |
306 | printk(KERN_INFO "%s: Probing failed!, using 2KB!\n", eeprom_name); | |
307 | eeprom.size = EEPROM_2KB; | |
308 | } | |
309 | } /* read */ | |
310 | } | |
311 | } | |
312 | else | |
313 | { | |
314 | i2c_outbyte(0x00); | |
315 | if(!i2c_getack()) | |
316 | { | |
317 | /* No 8k */ | |
318 | eeprom.size = EEPROM_2KB; | |
319 | } | |
320 | else | |
321 | { | |
322 | i2c_start(); | |
323 | i2c_outbyte(0x81); | |
324 | if (!i2c_getack()) | |
325 | { | |
326 | eeprom.size = EEPROM_2KB; | |
327 | } | |
328 | else | |
329 | { | |
330 | /* It's a 8kB */ | |
331 | i2c_inbyte(); | |
332 | eeprom.size = EEPROM_8KB; | |
333 | } | |
334 | } | |
335 | } | |
336 | i2c_stop(); | |
337 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_16KB) | |
338 | eeprom.size = EEPROM_16KB; | |
339 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_8KB) | |
340 | eeprom.size = EEPROM_8KB; | |
341 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_2KB) | |
342 | eeprom.size = EEPROM_2KB; | |
343 | #endif | |
344 | ||
345 | switch(eeprom.size) | |
346 | { | |
347 | case (EEPROM_2KB): | |
348 | printk("%s: " EETEXT " i2c compatible 2kB eeprom.\n", eeprom_name); | |
349 | eeprom.sequential_write_pagesize = 16; | |
350 | eeprom.select_cmd = 0xA0; | |
351 | break; | |
352 | case (EEPROM_8KB): | |
353 | printk("%s: " EETEXT " i2c compatible 8kB eeprom.\n", eeprom_name); | |
354 | eeprom.sequential_write_pagesize = 16; | |
355 | eeprom.select_cmd = 0x80; | |
356 | break; | |
357 | case (EEPROM_16KB): | |
358 | printk("%s: " EETEXT " i2c compatible 16kB eeprom.\n", eeprom_name); | |
359 | eeprom.sequential_write_pagesize = 64; | |
360 | eeprom.select_cmd = 0xA0; | |
361 | break; | |
362 | default: | |
363 | eeprom.size = 0; | |
364 | printk("%s: Did not find a supported eeprom\n", eeprom_name); | |
365 | break; | |
366 | } | |
367 | ||
368 | ||
369 | ||
370 | eeprom_disable_write_protect(); | |
371 | ||
372 | return 0; | |
373 | } | |
374 | ||
375 | /* Opens the device. */ | |
1da177e4 LT |
376 | static int eeprom_open(struct inode * inode, struct file * file) |
377 | { | |
32ea086b | 378 | if(iminor(inode) != EEPROM_MINOR_NR) |
1da177e4 | 379 | return -ENXIO; |
32ea086b | 380 | if(imajor(inode) != EEPROM_MAJOR_NR) |
1da177e4 LT |
381 | return -ENXIO; |
382 | ||
383 | if( eeprom.size > 0 ) | |
384 | { | |
385 | /* OK */ | |
386 | return 0; | |
387 | } | |
388 | ||
389 | /* No EEprom found */ | |
390 | return -EFAULT; | |
391 | } | |
392 | ||
393 | /* Changes the current file position. */ | |
394 | ||
395 | static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig) | |
396 | { | |
397 | /* | |
8d59dc11 | 398 | * orig 0: position from beginning of eeprom |
1da177e4 LT |
399 | * orig 1: relative from current position |
400 | * orig 2: position from last eeprom address | |
401 | */ | |
402 | ||
403 | switch (orig) | |
404 | { | |
405 | case 0: | |
406 | file->f_pos = offset; | |
407 | break; | |
408 | case 1: | |
409 | file->f_pos += offset; | |
410 | break; | |
411 | case 2: | |
412 | file->f_pos = eeprom.size - offset; | |
413 | break; | |
414 | default: | |
415 | return -EINVAL; | |
416 | } | |
417 | ||
418 | /* truncate position */ | |
419 | if (file->f_pos < 0) | |
420 | { | |
421 | file->f_pos = 0; | |
422 | return(-EOVERFLOW); | |
423 | } | |
424 | ||
425 | if (file->f_pos >= eeprom.size) | |
426 | { | |
427 | file->f_pos = eeprom.size - 1; | |
428 | return(-EOVERFLOW); | |
429 | } | |
430 | ||
431 | return ( file->f_pos ); | |
432 | } | |
433 | ||
434 | /* Reads data from eeprom. */ | |
435 | ||
436 | static int eeprom_read_buf(loff_t addr, char * buf, int count) | |
437 | { | |
82f3952c | 438 | return eeprom_read(NULL, buf, count, &addr); |
1da177e4 LT |
439 | } |
440 | ||
441 | ||
442 | ||
443 | /* Reads data from eeprom. */ | |
444 | ||
445 | static ssize_t eeprom_read(struct file * file, char * buf, size_t count, loff_t *off) | |
446 | { | |
447 | int read=0; | |
82f3952c | 448 | unsigned long p = *off; |
1da177e4 LT |
449 | |
450 | unsigned char page; | |
451 | ||
452 | if(p >= eeprom.size) /* Address i 0 - (size-1) */ | |
453 | { | |
454 | return -EFAULT; | |
455 | } | |
456 | ||
4f0447b8 | 457 | if (mutex_lock_interruptible(&eeprom.lock)) |
7e920426 | 458 | return -EINTR; |
1da177e4 | 459 | |
1da177e4 LT |
460 | page = (unsigned char) (p >> 8); |
461 | ||
462 | if(!eeprom_address(p)) | |
463 | { | |
464 | printk(KERN_INFO "%s: Read failed to address the eeprom: " | |
465 | "0x%08X (%i) page: %i\n", eeprom_name, (int)p, (int)p, page); | |
466 | i2c_stop(); | |
467 | ||
468 | /* don't forget to wake them up */ | |
4f0447b8 | 469 | mutex_unlock(&eeprom.lock); |
1da177e4 LT |
470 | return -EFAULT; |
471 | } | |
472 | ||
473 | if( (p + count) > eeprom.size) | |
474 | { | |
475 | /* truncate count */ | |
476 | count = eeprom.size - p; | |
477 | } | |
478 | ||
479 | /* stop dummy write op and initiate the read op */ | |
480 | i2c_start(); | |
481 | ||
482 | /* special case for small eeproms */ | |
483 | if(eeprom.size < EEPROM_16KB) | |
484 | { | |
485 | i2c_outbyte( eeprom.select_cmd | 1 | (page << 1) ); | |
486 | } | |
487 | ||
488 | /* go on with the actual read */ | |
489 | read = read_from_eeprom( buf, count); | |
490 | ||
491 | if(read > 0) | |
492 | { | |
82f3952c | 493 | *off += read; |
1da177e4 LT |
494 | } |
495 | ||
4f0447b8 | 496 | mutex_unlock(&eeprom.lock); |
1da177e4 LT |
497 | return read; |
498 | } | |
499 | ||
500 | /* Writes data to eeprom. */ | |
501 | ||
502 | static int eeprom_write_buf(loff_t addr, const char * buf, int count) | |
503 | { | |
82f3952c | 504 | return eeprom_write(NULL, buf, count, &addr); |
1da177e4 LT |
505 | } |
506 | ||
507 | ||
508 | /* Writes data to eeprom. */ | |
509 | ||
510 | static ssize_t eeprom_write(struct file * file, const char * buf, size_t count, | |
511 | loff_t *off) | |
512 | { | |
513 | int i, written, restart=1; | |
514 | unsigned long p; | |
515 | ||
516 | if (!access_ok(VERIFY_READ, buf, count)) | |
517 | { | |
518 | return -EFAULT; | |
519 | } | |
520 | ||
7e920426 | 521 | /* bail out if we get interrupted */ |
4f0447b8 | 522 | if (mutex_lock_interruptible(&eeprom.lock)) |
7e920426 | 523 | return -EINTR; |
1da177e4 LT |
524 | for(i = 0; (i < EEPROM_RETRIES) && (restart > 0); i++) |
525 | { | |
526 | restart = 0; | |
527 | written = 0; | |
82f3952c | 528 | p = *off; |
1da177e4 LT |
529 | |
530 | ||
531 | while( (written < count) && (p < eeprom.size)) | |
532 | { | |
533 | /* address the eeprom */ | |
534 | if(!eeprom_address(p)) | |
535 | { | |
536 | printk(KERN_INFO "%s: Write failed to address the eeprom: " | |
537 | "0x%08X (%i) \n", eeprom_name, (int)p, (int)p); | |
538 | i2c_stop(); | |
539 | ||
540 | /* don't forget to wake them up */ | |
4f0447b8 | 541 | mutex_unlock(&eeprom.lock); |
1da177e4 LT |
542 | return -EFAULT; |
543 | } | |
544 | #ifdef EEPROM_ADAPTIVE_TIMING | |
545 | /* Adaptive algorithm to adjust timing */ | |
546 | if (eeprom.retry_cnt_addr > 0) | |
547 | { | |
548 | /* To Low now */ | |
549 | D(printk(">D=%i d=%i\n", | |
550 | eeprom.usec_delay_writecycles, eeprom.usec_delay_step)); | |
551 | ||
552 | if (eeprom.usec_delay_step < 4) | |
553 | { | |
554 | eeprom.usec_delay_step++; | |
555 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
556 | } | |
557 | else | |
558 | { | |
559 | ||
560 | if (eeprom.adapt_state > 0) | |
561 | { | |
562 | /* To Low before */ | |
563 | eeprom.usec_delay_step *= 2; | |
564 | if (eeprom.usec_delay_step > 2) | |
565 | { | |
566 | eeprom.usec_delay_step--; | |
567 | } | |
568 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
569 | } | |
570 | else if (eeprom.adapt_state < 0) | |
571 | { | |
572 | /* To High before (toggle dir) */ | |
573 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
574 | if (eeprom.usec_delay_step > 1) | |
575 | { | |
576 | eeprom.usec_delay_step /= 2; | |
577 | eeprom.usec_delay_step--; | |
578 | } | |
579 | } | |
580 | } | |
581 | ||
582 | eeprom.adapt_state = 1; | |
583 | } | |
584 | else | |
585 | { | |
586 | /* To High (or good) now */ | |
587 | D(printk("<D=%i d=%i\n", | |
588 | eeprom.usec_delay_writecycles, eeprom.usec_delay_step)); | |
589 | ||
590 | if (eeprom.adapt_state < 0) | |
591 | { | |
592 | /* To High before */ | |
593 | if (eeprom.usec_delay_step > 1) | |
594 | { | |
595 | eeprom.usec_delay_step *= 2; | |
596 | eeprom.usec_delay_step--; | |
597 | ||
598 | if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step) | |
599 | { | |
600 | eeprom.usec_delay_writecycles -= eeprom.usec_delay_step; | |
601 | } | |
602 | } | |
603 | } | |
604 | else if (eeprom.adapt_state > 0) | |
605 | { | |
606 | /* To Low before (toggle dir) */ | |
607 | if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step) | |
608 | { | |
609 | eeprom.usec_delay_writecycles -= eeprom.usec_delay_step; | |
610 | } | |
611 | if (eeprom.usec_delay_step > 1) | |
612 | { | |
613 | eeprom.usec_delay_step /= 2; | |
614 | eeprom.usec_delay_step--; | |
615 | } | |
616 | ||
617 | eeprom.adapt_state = -1; | |
618 | } | |
619 | ||
620 | if (eeprom.adapt_state > -100) | |
621 | { | |
622 | eeprom.adapt_state--; | |
623 | } | |
624 | else | |
625 | { | |
626 | /* Restart adaption */ | |
627 | D(printk("#Restart\n")); | |
628 | eeprom.usec_delay_step++; | |
629 | } | |
630 | } | |
631 | #endif /* EEPROM_ADAPTIVE_TIMING */ | |
632 | /* write until we hit a page boundary or count */ | |
633 | do | |
634 | { | |
635 | i2c_outbyte(buf[written]); | |
636 | if(!i2c_getack()) | |
637 | { | |
638 | restart=1; | |
639 | printk(KERN_INFO "%s: write error, retrying. %d\n", eeprom_name, i); | |
640 | i2c_stop(); | |
641 | break; | |
642 | } | |
643 | written++; | |
644 | p++; | |
645 | } while( written < count && ( p % eeprom.sequential_write_pagesize )); | |
646 | ||
647 | /* end write cycle */ | |
648 | i2c_stop(); | |
649 | i2c_delay(eeprom.usec_delay_writecycles); | |
650 | } /* while */ | |
651 | } /* for */ | |
652 | ||
4f0447b8 | 653 | mutex_unlock(&eeprom.lock); |
82f3952c | 654 | if (written == 0 && p >= eeprom.size){ |
1da177e4 LT |
655 | return -ENOSPC; |
656 | } | |
82f3952c | 657 | *off = p; |
1da177e4 LT |
658 | return written; |
659 | } | |
660 | ||
661 | /* Closes the device. */ | |
662 | ||
663 | static int eeprom_close(struct inode * inode, struct file * file) | |
664 | { | |
665 | /* do nothing for now */ | |
666 | return 0; | |
667 | } | |
668 | ||
669 | /* Sets the current address of the eeprom. */ | |
670 | ||
671 | static int eeprom_address(unsigned long addr) | |
672 | { | |
673 | int i; | |
674 | unsigned char page, offset; | |
675 | ||
676 | page = (unsigned char) (addr >> 8); | |
677 | offset = (unsigned char) addr; | |
678 | ||
679 | for(i = 0; i < EEPROM_RETRIES; i++) | |
680 | { | |
681 | /* start a dummy write for addressing */ | |
682 | i2c_start(); | |
683 | ||
684 | if(eeprom.size == EEPROM_16KB) | |
685 | { | |
686 | i2c_outbyte( eeprom.select_cmd ); | |
687 | i2c_getack(); | |
688 | i2c_outbyte(page); | |
689 | } | |
690 | else | |
691 | { | |
692 | i2c_outbyte( eeprom.select_cmd | (page << 1) ); | |
693 | } | |
694 | if(!i2c_getack()) | |
695 | { | |
696 | /* retry */ | |
697 | i2c_stop(); | |
698 | /* Must have a delay here.. 500 works, >50, 100->works 5th time*/ | |
699 | i2c_delay(MAX_WRITEDELAY_US / EEPROM_RETRIES * i); | |
700 | /* The chip needs up to 10 ms from write stop to next start */ | |
701 | ||
702 | } | |
703 | else | |
704 | { | |
705 | i2c_outbyte(offset); | |
706 | ||
707 | if(!i2c_getack()) | |
708 | { | |
709 | /* retry */ | |
710 | i2c_stop(); | |
711 | } | |
712 | else | |
713 | break; | |
714 | } | |
715 | } | |
716 | ||
717 | ||
718 | eeprom.retry_cnt_addr = i; | |
719 | D(printk("%i\n", eeprom.retry_cnt_addr)); | |
720 | if(eeprom.retry_cnt_addr == EEPROM_RETRIES) | |
721 | { | |
722 | /* failed */ | |
723 | return 0; | |
724 | } | |
725 | return 1; | |
726 | } | |
727 | ||
728 | /* Reads from current address. */ | |
729 | ||
730 | static int read_from_eeprom(char * buf, int count) | |
731 | { | |
732 | int i, read=0; | |
733 | ||
734 | for(i = 0; i < EEPROM_RETRIES; i++) | |
735 | { | |
736 | if(eeprom.size == EEPROM_16KB) | |
737 | { | |
738 | i2c_outbyte( eeprom.select_cmd | 1 ); | |
739 | } | |
740 | ||
741 | if(i2c_getack()) | |
742 | { | |
743 | break; | |
744 | } | |
745 | } | |
746 | ||
747 | if(i == EEPROM_RETRIES) | |
748 | { | |
749 | printk(KERN_INFO "%s: failed to read from eeprom\n", eeprom_name); | |
750 | i2c_stop(); | |
751 | ||
752 | return -EFAULT; | |
753 | } | |
754 | ||
755 | while( (read < count)) | |
756 | { | |
757 | if (put_user(i2c_inbyte(), &buf[read++])) | |
758 | { | |
759 | i2c_stop(); | |
760 | ||
761 | return -EFAULT; | |
762 | } | |
763 | ||
764 | /* | |
765 | * make sure we don't ack last byte or you will get very strange | |
766 | * results! | |
767 | */ | |
768 | if(read < count) | |
769 | { | |
770 | i2c_sendack(); | |
771 | } | |
772 | } | |
773 | ||
774 | /* stop the operation */ | |
775 | i2c_stop(); | |
776 | ||
777 | return read; | |
778 | } | |
779 | ||
780 | /* Disables write protection if applicable. */ | |
781 | ||
782 | #define DBP_SAVE(x) | |
783 | #define ax_printf printk | |
784 | static void eeprom_disable_write_protect(void) | |
785 | { | |
786 | /* Disable write protect */ | |
787 | if (eeprom.size == EEPROM_8KB) | |
788 | { | |
789 | /* Step 1 Set WEL = 1 (write 00000010 to address 1FFFh */ | |
790 | i2c_start(); | |
791 | i2c_outbyte(0xbe); | |
792 | if(!i2c_getack()) | |
793 | { | |
794 | DBP_SAVE(ax_printf("Get ack returns false\n")); | |
795 | } | |
796 | i2c_outbyte(0xFF); | |
797 | if(!i2c_getack()) | |
798 | { | |
799 | DBP_SAVE(ax_printf("Get ack returns false 2\n")); | |
800 | } | |
801 | i2c_outbyte(0x02); | |
802 | if(!i2c_getack()) | |
803 | { | |
804 | DBP_SAVE(ax_printf("Get ack returns false 3\n")); | |
805 | } | |
806 | i2c_stop(); | |
807 | ||
808 | i2c_delay(1000); | |
809 | ||
810 | /* Step 2 Set RWEL = 1 (write 00000110 to address 1FFFh */ | |
811 | i2c_start(); | |
812 | i2c_outbyte(0xbe); | |
813 | if(!i2c_getack()) | |
814 | { | |
815 | DBP_SAVE(ax_printf("Get ack returns false 55\n")); | |
816 | } | |
817 | i2c_outbyte(0xFF); | |
818 | if(!i2c_getack()) | |
819 | { | |
820 | DBP_SAVE(ax_printf("Get ack returns false 52\n")); | |
821 | } | |
822 | i2c_outbyte(0x06); | |
823 | if(!i2c_getack()) | |
824 | { | |
825 | DBP_SAVE(ax_printf("Get ack returns false 53\n")); | |
826 | } | |
827 | i2c_stop(); | |
828 | ||
829 | /* Step 3 Set BP1, BP0, and/or WPEN bits (write 00000110 to address 1FFFh */ | |
830 | i2c_start(); | |
831 | i2c_outbyte(0xbe); | |
832 | if(!i2c_getack()) | |
833 | { | |
834 | DBP_SAVE(ax_printf("Get ack returns false 56\n")); | |
835 | } | |
836 | i2c_outbyte(0xFF); | |
837 | if(!i2c_getack()) | |
838 | { | |
839 | DBP_SAVE(ax_printf("Get ack returns false 57\n")); | |
840 | } | |
841 | i2c_outbyte(0x06); | |
842 | if(!i2c_getack()) | |
843 | { | |
844 | DBP_SAVE(ax_printf("Get ack returns false 58\n")); | |
845 | } | |
846 | i2c_stop(); | |
847 | ||
848 | /* Write protect disabled */ | |
849 | } | |
850 | } | |
84c3e5bf | 851 | device_initcall(eeprom_init); |